Manufacture of plates and sheets.



W UNITED STATES PATENT OFFICE.

STEWART A. DAVIS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOB 'I'O AMERICAN SHEET & TIN PLATE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION 0F NEW Patented Nov. 30, 1909.

JERSEY.

MANUFACTURE OF PLATES AND SHEETS.

941,861,, Specification of Letters Patent. No Drawing. Application filed larch 15, 1909. Serial No. 488,488.

To all whom it may concern:

Be it known that I, STEWART A. DAVIS, of Pittsburg, in the count of Allegheny and State of Pennsylvania, ave invented a new and useful Improvement in the Manufacture of Plates and Sheets, of which the following is a full, clear, and exact description.

My invention relates to the manufacture of metal plates and sheets and more particularly to a novel method of finishing the same to obtain a highly polished blued surface. 7

The object of my invention is to simplify the methods heretofore in use by reducing the number of steps necessary to produce the desired finish, thereby materially reducing the time, labor and cost of the 0 eration and increasing the output of the mil A further object is to provide a method of this character by which a su erior uniform finish is given the sheets an plates.

In the practice of my invention, after the plates and sheets have been hot-rolled in the usual manner, they are placed in an annealing box and brought up to an annealing temperature. The box is then removed from the furnace and steam is introduced therein to cause oxidation of the surfaces of the plates while they are cooling, and producing what is known as a steam blued finish. The cooled plates are then given one or more roll passes, preferably two. They are then again annealed, after which they are allowed to partially cool in the annealing box out oi? contact with the atmosphere.

They are then removed from the box in a partially cool state and are given one or more finishing roll passes, preferably at a temperature of about 350 F. to 1000 F. I claim:

1. The herein described method of treating metal plates or sheets, which consists in annealin them, and submitting them to the action 0 steam while they are cooling, then cold rolling them, then again annealing, and then roll finishing, substantially as described.

2. The herein described method of treating metal plates or sheets, which consists in annealing them and submitting them to the action of steam while they are cooling, then cold rollin them, then again annealing, and finally rolling them before they have cooled, substantially as described.

3. The herein described method of treating metal plates or sheets, which consists in annealing them, then submitting them while cooling to an oxidizin atmosphere containing steam, then cold ro ling them, then again annealin and allowing them to partially cool in t e annealing box, and finally rollfinishing the partially cooled plates or sheets, substantially as described.

In testimony whereof, I have hereunto set my hand.

S. A. DAVE S.

Witnesses CLAIR KELLY, G. C. KIMBALL. 

